Mud-pump piston



June 11, 1929. A. z. RASH MUD PUMP PISTON Filea March 14, 1928 2 Sheets-Shut 1 June 11, 1929. A. z. RASH 1,716,900

F MUD PUMP PI'STON Filed March 14, 1928 2 Sheets-Sheet 2 Patented June 11, 1929.

PATENT OFFICE.

ALBERT Z. BASH, OF HOLLYWOOD, CALIFORNIA.

MUD-PUMP PISTON.

Application filed March 14, 1928. Serial No. 261,519.

My invention is a mud pump piston of a type adapted to expand by the pressure on the end of the piston.

An object of my invention is the construction of a mud pump piston in which the piston expands at both ends when pressure is applied only to one end, and as such pressure alternates from end to end in the pump ing operation, there is an equal expansion of the piston at such opposite ends simultaneously.

A further object of my invention is to construct the ends of the piston with metal segments and to have expansion rubber between the end segments, and in this connection a further object of my invention is to cause the expansion of the rubber in proportion as the metal segments wear away by the continuous friction against the liner 0 of the pump.

A further object 01 my invention is to have a substantial core connected to the piston or pump rod and such core takes the direct or major portion of the pressure of the pumping action, this being transmitted from the segments and the rubber adjacent thereto.

A further object of my invention is to have the segments at the ends of the piston protect the rubber from undue wear and from excess expansion and a further Object is to have the rubber expand in proportion as the segments are worn and expanded.

In constructing my invention I have a substantial core or body structure secured to the piston or pump rod, this core or body having a central annular abutment structure. The ends of the piston adjacent the liner are formed of metallic rings which are divided into a plurality of segments, of which I find that four segments to a complete ring are satisfactory. Each of these segments on the inner face thereof carries a substantial arm which has a ball and socket connection with an abutment of the core.

Each of the arms is provided with shoulders extending laterally therefrom in a more 7 or less radial direction, and from each of these shoulders there are diagonal pressuretransmitting pins that extend diagonally to the shoulders on the arms extending inwardly from the segments on the opposite ends of the piston. These pins pass through holes in the abutment structure of the core andwhen the segments are pressed outwardly, due to the pressure on the end from the pumping operation and to their wear, the rocking action on the ball and socket connection with the abutment causes the ments on one end to operate the segments on the other end through the medium of the pressure-transmitting pins, thus expanding the opposite end se ments. My invention is illustrated in the accompanying drawings, in which Figure 1 is a side elevation of my invention as if taken in the direction of the arrow 1 of Fig. 2, partly broken away.

Fig. 2 is an end elevation of Fig. 1 taken in the direction of the arrow 2.

Fig. 3 is a vertical longitiulinal section. taken substantially on the line 33 of Fig.

'2, withthe rubber filling.

Fig. 4 is a side elevation of the core as if taken in the direction of the arrow 4 of Fig. 5.

Fig. 5 is an end View of the core of Fig. 4 as if taken in. the direction of arrow 5 of Fig. 4.

Fig. 6 is a side elevation of one of the seg ments taken in the direction of the arrow 6 of Fig. 7.

Fig. 7 is a rear elevation of Fig. 6 taken in the direction of the arrow 7.

Fig. 8 is a plan of one of the segments taken in the direction of the arrow 8 of Fig. 6.

The pump liner is indicated by the numeral 11 and the piston has a piston rod 12 having preferably a tapered section 13. This has a core 14 fitted thereon, the core being secured in position by nuts and lock nuts 15 on the screw-threaded end 16 of the piston rod.

The core is constructed substantially as follows, having reference particularly to Figs. 4: and 5: This has a central annular abutment portion 17, which is illustrated as having a cylindrical periphery 18 and being of a substantial measurement, considered longitudinally of the core. The ends 19 are of a reduced diameter and preferably cylindrical. The core has an intermediate section 20 spaced between the abutment section and the ends 19, and extending outwardly from this section there are sets of lugs 21, the illustration showing four sections.

The opposite faces of the abutment sec tion of the core has pairs of sockets 22, these sockets being arranged to be spaced between the lugs 21 and adjacent to these sockets there are diagonal openings or passages 23 extending through the abutment part of the core from one side of the face to the other (note Figs. 4 and 5).

At opposite ends of the piston. there are metal rings, designated generally by the nu meral 24:. Each of these rings is constructed of a. plurality of segments, designated generally by the numeral 25, the segments all being similar, and in the illustration four being; shown. These segments are constructed substantially as follows:-

An arcshaped metal structure 26 has the outer periphery 27 concentric with the piston rod, and of the same curvature as the interior cylindrical surface of the liner 11. The inner surface 23 may also be concentric to the outer surface if desired, although this is immaterial. The ends of each segment are formed-with a notched or rabbeted section 29 and a tongue section 30, these interfitting and forming overlapping rabbeted type of joints, as indicated at 31 (note Figs. 1, 6 and 7).

Extending rearwardly from each of the arcuate plates of the segments there is a substantial arm 32, such arm having an opening 33 therethrough. These arms terminate in knob or ball structures 34, there being two for each arm and such balls fit in the sockets 22 on the faces of the abutment portion 17 of the core,

Shoulder structures 35' extend outwardly and inwardly from each of the arms, con sidered in a radial direction, and these shoulders have abutment edges 36 for a purpose hereunder set forth, and have fiat surfaces 37 adjacent their; outer ends (note Figs. 6, 7 and 1). There are sets of pins 38 which extend through the diagonal holes 23 inthe abutment portion of the core and these pins at each end engage the outer shoulderof one of the segments and the inner shoulder of the segment on the other end of the piston, there being a set of two pins, thus interconnecting-the two segments in alignment at opposite ends of the piston (:note Figs. 1 and hen the device sofa-r described is assembled, the rings 24L being held in place in a: suitable mold with their outer periphery the correct diameter for the liner of the pump, the knobs or balls 34: are properly engaged inthe sockets 22 and the pins 38 are properly fitted. A filling of rubber 39 is then cast in the mold, filling around the core and inside the inner edge of the arcuate plates forming the segments, also filling in the open space 33 of the arms 32 of the segments and embedding all the interior construction, such as the arms 32,

the shoulders 34 and the pins 38, thus forming the piston into a mass structure in which the metal parts are held in proper relation to the core by the rubber, until the piston may be placed in the pump.

The manner of functioning and operation of my piston is substantially as follows: When the pressure in the pumping action is exerted on one end of the piston, it tends to cause an outward pivoting movement oft-he segments, suchsegments pivoting on the balls 3% mounted in the sockets 22. As the metal of the; segments becomes Worn, this tilting causes the flat surface 37 of the shoulders 35 on the arms 32 of each of the segments on the pressure-receiving face to press onone of the diagonal pins for each segment; that is, the shoulder extending outwardly in a radial direction presses on one of these diagonal pins and causes such pin to press on the inner shoulder of the segment on the opposite end of the piston, thereby causing such ment on the side opposite the pressure to be pressed outwardly against the liner, this rocking on the balls 34- in the sockets 22.

Itwill therefore be seen that as the pressure at one end of the pistons acts on all of the segments at each end causing these to press out slightly and to increase their upward tilt in accordance with the wear, such outer pressure is communicated to the corresponding segments at the other end of the piston, causing theseto press outwardly.

Therefore,'the wearing or rubbing action of the piston is taken by the metal segments at each end of the piston. become worn down in time and the joint 31 becomes slightly open, but this is immaterial as such jo-ints are formed with the rabbet and tongue type of connection.

The lugs 21 function to hold and center the arms 32 of the segments- 25. These arms have lateral projections 40 which have a curved bearing surface ll, this bearing surface being formed on a circle concentric with the point of oscillation of the arms and segments in the sockets 22. Such curved surfaces bear against the flat surface 4-2 on the inside of each of the lugs 21. The faces of such lugs function to hold the arms 32 centered and prevent lateral shiftinga Hence, when there is a pressure brought on one side of the piston and this is transinitted through the pins to the shoulders of the arms car 'ying the segments on the other end of the piston, the outward thrust is taken by the lugs 21 on account of the bearing surfacc' ll thrusting thercagainst. This arrangement of the curved surface ll allows free outward inclination of the segment as the metal of the arcuate plate of the segments wears,

Various changes may be made in the prin These, of course,

ciples of my invention without departing from the spirit thereof, as set forth in the description, drawings and claims.

I claim:

1. A mud pump piston comprising in combination a supporting structure having me tallic rings at the opposite enes adapted to contact with the liner of a pump, said rings being adapted to expand outwardly in accordance with their wear, means to cause the rings on one end to expand due to pressure on such end, and means to cause the ring at the other end of the piston to expand due to th pressure on the ring at the firstmentioned pressure end.

2. A mud pump piston comprising in combination a supporting structure having rings at opposite ends adapted to contact with the liner of a pump, said rings being expandible in segments, means to expand the rings on one end due to pressure on such end of the piston, and means to expand the rings on the other end of the piston due to the movement of the rings on the first mentioned pressure end.

3. A mud pump piston comprising in combination a supporting structure having a ring at each end to engage the. liner of a pump, said rings having a plurality of segments with joints therebetween whereby each segment may expand independently of an adjacent segment, means to cause the segments at one end of the piston to expand due to pressure against such end, and means to cause the segments at the other end to expand due to the movement of the segments at the first mentioned pressure end.

4. A mud pump piston comprising in combination a piston rod having a core thereon, a structure surrounding such core having an expansible ring at each end to contact with the liner of a pump, means interengaging the core and the ring at one end to cause the expansion of such ring due to pressure on such end, means interengaging the ring at the opposite end and the core, and a motion transmittin means between the means interengaging the core and the rings at opposite ends of the piston.

5. A mud pump piston comprising in combination a piston rod having a core thereon, a structure surrounding such core having an expansible ring at each end of the piston to engage a liner, each ring being formed in outwardly expanding segments, pivotally mounted arm structures engaging the segments at each. end and the core, and means to actuate the segments at one end of the core by a transmission of pressure exerted on the other end of the piston.

6. A mud pump piston, as claimed in claim 5, the structure surrounding the core comprising rubber like resilient material, the said arm like structures being embedded in such material.

7. A mud pump piston comprising in combination a piston rod having a core thereon with an annular abutment section, a ring at each end of the piston to engage the liner' of the pump, each ring having outwardly expanding segments, thrust arms interconnecting each segment and the abutment portion, and means to transmit motion to the arm structures at one end of the piston due to pressure on the segments at the other end of the piston.

8. A mud pump piston, as claimed in claim 7 the means to transmit pressure comprising slidable pins and said pins engaging outwardly projecting shoulders on the said arm structures.

9. A mud pump piston comprising in combination a piston rod having a core with an annular abutment portion, a supporting structure around the core, rings at each end of the supportingstructure forming portions at opposite ends of the piston, such rings engaging the liner of the pump and each ring being made in outwardly expanding segments, the core having guide and thrust lugs, pressure transmitting arm structures connected to each segment and having a rocking bearing on the abutment portion of the core, said lugs centering said arms, and shoulders extending outwardly from the arms, pins slidably mounted in relation to the core and engaging diagonally opposite shoulders.

10. A mud pump piston, as claimed in claim 9, the lugs having a tln'ust-receiving surface and the arms having laterally extending projections bearing against the said surface of the lugs and preventing shifting of the arms and segments on the end of the piston opposite to that receiving the pressure.

11. A mud pump piston comprising in combination a piston rod, a body. of resilient rubber like material, means interconnecting said material and the piston rod, a ring at each end of the piston partly embedded in said material and engaging the liner of a pump, each ring being expandible, and interconnecting means from the ring at one end of the piston to the ring at the other through said material and embedded in said material to cause an outward expanding movement of the ring at one end of the piston due to pressure on the ring at the other end of the piston.

12. A mud pump piston, as claimed in claim 11, each ring being formed in a plurality of separate segments with joints therebetween, each segment being expandible outwardly independently of an adjacent segment.

13. A mud pump piston comprising in combination a piston rod having a core, a. body of resilient rubber like material surrounding and secured to the core embedding a part of such core, an expanding ring at each end of the piston partly embedded in the material and engaging the liner, thrusttransmitting means between each ring and the core, and means interconnecting the thrust-transmitting means at one end of the piston to that at the other end of the piston, said thrust-transmitting means and interconnecting means being embedded in the rubber like material.

14. A mud pump piston comprising in combination a core adapted for securing to a piston rod having an annular abutment portion, a body of rubber like material surrounding and partly embedding the core, a ring at each end of the piston partly embedded 'in such material, such ring having a plurality of outwardly expanding segments, a thrust-transmitting arm connected to each segment and bearing against the said abutment portion having a rocking movement, and pressure transmitting means between the arms connected to the segments at one end of the piston and the arms eonneeted to the segments at the other end of the piston, the said arms and PIQSSHI'O-tlitlL mitting means being embedded in the said material.

15. A mud pump piston, as claimed in claim 14, the pressure-transmitt-ing means comprising pins slidably mounted in holes in the core and arranged diagonally, the ends of the pins engaging outwardly extending shoulders on each of the arms, and means interconnecting the arms and the se ments to prevent their outward displacement due to transmission of pressure from one end or" the piston to the other.

16(A mud pump piston comprising in combination a core adapted to be secured to a piston rod and having an annular abutment portion, a segmental'expanding ring at each end of the piston partly embedded in said material, a thrust arm connected to each segment and having. a pivotal thrust bearing on the abutment portion, each arm having an outwardly extending shoulder in a radial direction, pins slidably mounted in holes in the core and engaging diagonally opposite shoulders, means connected to the core to prevent their outward displacement, the arms, the pins and the said means on the core being embedded in said material.

17. A mud pump piston, as claimed in claim 16, the means on the core interengaging the arms comprising outwardly extending lugs on the core and laterally extending projections on each of the arms, said projections interengaging the lugs wher by the projections have a sliding movement in relation to the lugs on the outward movement of the segments of the rings.

In testimony whereof I have signed my name to this specification.

ALBERT Z. BASH. 

